To determine its results, the report gauged the happiness levels of thousands of individuals from 156 nations from their responses to the Gallup World Poll.

Countries were ranked according to six key criteria: GDP per capita, social support, life expectancy, freedom to make life choices, generosity, and freedom from corruption.

The report also considered happiness inequality, to see how happiness levels varied between people from the same countries.

"The reports review the state of happiness in the world today and show how the new science of happiness explains personal and national variations in happiness," the report reads. "They reflect a new worldwide demand for more attention to happiness as a criteria for government policy."

13. Burkina Faso

12. Uganda

Thomson Reuters

Uganda declared independence from Britain in 1962, and has since experienced a military coup and violent dictatorship. Internationally, the country's government has a reputation for its homophobic views of the LGBT community, according to the BBC.

7. Guinea

REUTERS

Guineans are among the poorest people in West Africa, while the country's economy has also suffered from the volume of refugees that have come from neighbouring countries Liberia and Sierra Leone, according to the BBC.

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6. Rwanda

Associated Press

Rwanda's 100-day genocide of 1994, in which thousands of people were killed and many left without homes, still bears on the country today.